Rabdosia rubescens (Hemsl.) Hara (donglingcao) (family Labiatae), formerly known as Isodon rubescens, is a Chinese medicinal herb. The aerial parts of R. rubescens and other species of the same genus were observed to have the functions of clearing heat and toxicity, nourishing “yin”, removing blood stasis, and relieving swelling.
R. rubescens has been used to treat stomach ache, sore throat, cough, esophagal cancer, breast cancer, liver cancer, and prostate cancer (Yu et al., 1995, Oncology Reports 2(4): 571-575; Zhong Hua Ben Cao, 1999, vol. 7, pp.150-514, and 553-561, Shanghai Science and Technology Press). R. rubescens increased survival and reduced side effects in patients with esophageal carcinoma. (Wang et al., 1993, Chung-Hua Chung Lin TSA Chin. 1993, 15(4), 300-302). R. rubescens is one of the eight herbs used in PC-SPES, an herbal formula promoted as a treatment for prostate cancer, see U.S. Pat. No. 5,665,393.
A number of studies reported attempts to identify biomedically useful compounds from E. rubescens. Rubescensin A (oridonin) and rubescensin B (ponicidin) are two compounds identified in R. rubescens extract, which have been tested for cytotoxicity against cancer cell lines in vitro. Both compounds have also been shown to be anti-angiogenic. (Meade-Tollin et al., 2004, Journal of Natural Products, 67(1): 2-4).
Citation or identification of any reference in this or any other section of this application shall not be construed as an admission that such reference is available as prior art to the present invention.